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Is My Yeast Infected?

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Truman42

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The sample on the left is US05 which I collected from my trub and washed and stepped it up before putting in this sample jar and into the fridge.

The sample on the right was harvested from a stubbie of Kooinda Black IPA and stepped up also.

Are the bubbles in the sample jar on the right a sign of infection or normal? Theyve both been in the fridge about 8 days.

Thanks.

infection.JPG
 

manticle

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Very hard to tell. Might have just got agitated. Making a starter and tasting/smelling that will be a better indicator. Visually, skins growing on top or excess ropy material in the wort will be better indicators. Smell and taste are paramount.

Not 100% sure the kooinda yeast will be much different from 05. I doubt it's a proprietrary yeast. Fents might tell you different (but he just had a month off booze so don't trust anything he says).
 

Truman42

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Very hard to tell. Might have just got agitated. Making a starter and tasting/smelling that will be a better indicator. Visually, skins growing on top or excess ropy material in the wort will be better indicators. Smell and taste are paramount.

Not 100% sure the kooinda yeast will be much different from 05. I doubt it's a proprietrary yeast. Fents might tell you different (but he just had a month off booze so don't trust anything he says).
When I look up close there are sort of cloudy streaks of yeast in the wort, is that what you mean by ropey material?

Its sitting in the fridge door but that fridge is in the garage and not opened often.
 

manticle

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Rope like rope. Things join together and make stringy ropey stuff in the wort.

Leave it a few days and see what happens to the bubbles and to the possible rope.
Then make a DME starter with it. Let the starter ferment out and see if it tastes like young, extract unhopped beer or if it smells like fresh bread dough. If not - chuck it.

Alternatively, found out if the Kooinda brewery uses a yeast you can't easily find anywhere else (which I supsect they don't). If it's not super rare or expensive, just go back to the old adage - if in doubt, throw it out.
 

Truman42

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Rope like rope. Things join together and make stringy ropey stuff in the wort.

Leave it a few days and see what happens to the bubbles and to the possible rope.
Then make a DME starter with it. Let the starter ferment out and see if it tastes like young, extract unhopped beer or if it smells like fresh bread dough. If not - chuck it.

Alternatively, found out if the Kooinda brewery uses a yeast you can't easily find anywhere else (which I supsect they don't). If it's not super rare or expensive, just go back to the old adage - if in doubt, throw it out.
Ok will give that a try and see how it goes. Thanks once again..
 

Yob

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You stepped it up before storing it? Er. . Most people go the other way and step it up once they have taken it out of the fridge, the yeast will be usimg up their reserves and if storing longer than week or two you will need to do it again..

Yeast collected from the trub, and there should be plenty of it, is good to go for a few weeks as is, no need to srep it up at all, longest I've left it in the fridge and used it was about 2 weeks.

How did the starters smell/taste? That's the most accurate tool you have, smell and taste, give it a good shake and smell it, pour a little off and taste it, any suspicions, dump it and start again.

Mrs Malty will tell you how much compact yeast slurry you will need for your next brew, personally I've still not got round to building the stir plate as repitching normally is sufficient, if I'm at all sus I throw in a new packet. How many ml of yeasy slurry have you got in those pee jars?
 

Truman42

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You stepped it up before storing it? Er. . Most people go the other way and step it up once they have taken it out of the fridge, the yeast will be usimg up their reserves and if storing longer than week or two you will need to do it again..

Yeast collected from the trub, and there should be plenty of it, is good to go for a few weeks as is, no need to srep it up at all, longest I've left it in the fridge and used it was about 2 weeks.

How did the starters smell/taste? That's the most accurate tool you have, smell and taste, give it a good shake and smell it, pour a little off and taste it, any suspicions, dump it and start again.

Mrs Malty will tell you how much compact yeast slurry you will need for your next brew, personally I've still not got round to building the stir plate as repitching normally is sufficient, if I'm at all sus I throw in a new packet. How many ml of yeasy slurry have you got in those pee jars?
I did it mainly as an experiment as Im new to yeast and starters etc and just built myself a stir plate too.

I collected the yeast from the dregs of a stubbie and wanted to increase the quantity to a suitable size that I could then create a 1 litre starter when I need it. I only had a few mms from the stubbie but have increased it to about 12mm in that sample jar.

It certainly tasted ok before I poured it off into the jar but haven't tasted it again since getting this bubbling on the surface.
 

Yob

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I only had a few mms from the stubbie but have increased it to about 12mm in that sample jar.
misread that bit, sorry, but you did also say you stepped up yeast from trub too ;)

Then make a DME starter with it. Let the starter ferment out and see if it tastes like young, extract unhopped beer or if it smells like fresh bread dough. If not - chuck it.
wat ee sed then B)
 

Muscovy_333

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I did it mainly as an experiment as Im new to yeast and starters etc and just built myself a stir plate too.

I collected the yeast from the dregs of a stubbie and wanted to increase the quantity to a suitable size that I could then create a 1 litre starter when I need it. I only had a few mms from the stubbie but have increased it to about 12mm in that sample jar.

It certainly tasted ok before I poured it off into the jar but haven't tasted it again since getting this bubbling on the surface.

If you stepped it and did not let it ferment right out for a couple of weeks it is likely your yeast is finishing off any residual sugar it can find.
Save your stepping prior to pitching.
 

Wolfy

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Are the bubbles in the sample jar on the right a sign of infection or normal? Theyve both been in the fridge about 8 days.
The bubbles - by themselves - mean nothing, the yeast is still alive, it is still active even if you've kept it chilled - likely it's just CO2 either being produced by the yeast or de-gassing from solution.
I'd be surprised if they used a different yeast for the Black IPA than they do for the APA so it may be that you've got two bottles of US05 there anyway. :)
 

mugley

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Kooinda use new dry US05 for every batch of pretty much everything. No reculturing.
 

pcmfisher

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Did you wash the wee out of both containers??
 

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